Mechanical pencil



y Feb. 7 1950 G. LYNN 2,496,554

MECHANICAL PENCIL Filed Deo. 18, 1946 2 Sheets-Sheet l Feb. 7, 1950 G.LYNN 2,496,554

MECHANICAL PENCIL Filed Dec. 18,4 1946 2 Sheets-Sheet 2 11 \/57 )SiC-4MQW/WW II////v Patented Fel). 7, 1950 UNITED `STATES PATENT OFFICEMECHANICAL PENCIL Gary Lynn, Melrose Park, Ill.

Application December 18, 1946, Serial No. 716,907

(Cl. 1Z0- 18) 6 Claims. l

This invention relates to mechanical pencils and is more particularlyconcerned with the provision of a pencil embodying means for guiding andfeeding relatively large diameter lead suitable for such uses as markingpackages, checking items, marking bowling scores, et cetera. In markingbowling scores, printing on packages, et cetera, it has heretofore beenthe practice to use crayons which, due to their enlarged diameters, mustbe provided with a sharpened point in order to provide legible writingor printing. Crayons are also objectionable as they become softened andbroken through use in hot weather.

The present invention contemplates the provision of a mechanical pencilembodying either a screw feed mechanism or a reciprocable clutch feedmechanism for progressively moving a relatively large diameter leadtoward the point of the pencil.

This invention further contemplates the provision of a mechanical pencilembodying a feed mechanism adapted to be enclosed within a twopiecehousing which, in turn, is inserted into and frictionally engaged withinthe barrel or body of the pencil.

This invention further contemplates the provision of means forpreventing relative longitudinal movement of the two pieces of the splithousing during or after assembly of same within the barrel of a pencil.

This invention embodies other novel features, details of constructionand arrangement of parts which are hereinafter set forth in thespecication and claims and illustrated in the accompanying drawingswherein:

Fig. 1 is a longitudinal sectional view showing a mechanical pencilembodying features of this invention.

Fig. 2 is a transverse sectional View taken along the line 2--2 of Fig.1.

Fig. 3 is a transverse sectional View taken along the line 3-3 of Fig.1.

Fig. 4 is a longitudinal sectional view showing a modified form of achecking pencil embodying features of this invention.

Fig. 5 is a transverse sectional View taken along the line 5-5 of Fig.4.

Fig. 6 is a transverse sectional View taken along the line 6-6 of Fig.4.

Referring now to the drawings for a better understanding of thisinvention and more particularly to Figs. 1, 2 and 3 therein, themechanical pencil is shown as comprising a lead guide tube 1 adapted toreceive a relatively large diameter lead 8. The lead guide tube I ispreferably 2 blanked and formed of relatively thin sheet metal toprovide a longitudinally extending slot 9 and a neck portion il ofreduced diameter to frictionally engage the lead 8.

A feed plug I2 is mounted for reciprocable movement within the leadguide tube i for moving the lead il outwardly through the reduced neckportion II. The feed plug I2 is provided with a feed shoulder I3 whichprojects outwardly through the longitudinally extending slot 9 forengagement within a helical groove Iii formed in a feed housing I6. Inorder to prevent breakage of parts, the helical groove lil terminates atits ends in run-out chambers Il and E8 which permit rotational movementof the feed housing I6 without imparting reciprocatory movement to thefeed plug i2. The feed housing Iii is also split longitudinally alongdiametrically opposed sides, as illustrated in Figs` 2 and 3, tofacilitate assembly and to reduce the cost of manufacture. By making thefeed housing in two halves, each section Ilia and It?) may beinexpensively formed by either die casting or stamping operations. Thesections ISa and Itb of the feed housing It are secured in properalignment by means of a head plug I9 formed with an annual flange 2l tobe received in arcuate aligning recesses 32e-22. The inner end of thehead plug I9 is formed with a cylindrical boss 23 for insertion into theinner end of the guide tube `I. The guide tube 'I is secured to thecylindrical boss 23 by welding -or brazing to form a relatively strong,rigid unitary structure adapted to be rotated within the split feedhousing I6.

A barrel 25 formed of plastic, metal or other suitable material isprovided to snugly and frictionally receive and engage the split feedhousing I6. The outer end of the barrel 2S is reduced at 2l and formedwith a reduced bore at 2s to receive the neck portion I I of the guidetube An aperture 29 is formed in the outer end of the barrel 26 for thepassage of the lead t.

If desired, a ring portion 3l of a clip 32 may be mounted on the splitfeed housing iii between the head portion 33 thereof and the inner endof the barrel 26. A band of thin metal sli is mounted over the inner endof the split feed housing it to enclose the ring portion 3l of the clip32. A suitable cap 36 formed of plastic or metal is pressed over thehead plug I9 and is secured against relative rotational or axialmovement therewith by means of a knurled surface 3'! formed on the plugI9. A helical compression spring 3S is mounted within the cylindricalboss 23 to urge the feed plug I2 outwardly to move the feed shoulder I33 out of the run-out chamber il and into the helical groove I4. Ifdesired, a tassie may be inserted through an opening 42 formed in theend of the cap 36 for threaded engagement at 43 in the head plug I9, inwhich event the clip 32 would be omitted from the pencil construction.

In the use of a pencil of the type shown and described, the lead 8 isforced outwardly through the guide tube l by means of relativerotational movement between the guide tube 'i and the split feed housingiii. When the feed plug l2 is in its inner position, as indicated inFig. l, the compression spring 38 acts to move the feed plug i2outwardly until the feed shoulder I3 moves into the helical groove Iii.When the feed shoulder i3 is disposed within the helical groove it willbe noted that relative movement between the guide tube l and the splitleed housing IG will cause reciprocable movement of the feed plug l2. As

the lead 8 becomes worn, the feed plug l2 will eventually come to restat the outer end of the guide tube l, with the feed shoulder i3 disposedwithin the run-out chamber i8. in refilling the pencil with a new lead,the feed plug is moved to its inner position, illustrated in Fig, l, anda. lead 8 is inserted into the guide tube l.

Figs. 4, and 6 illustrate a modified .form of this invention in whichthe pencil is shown as comprising a guide tube 5S to receive lead 32.

The guide tube 5! is enclosed within a split feed 0 housing 53 formed oftwo similar hal; sections 53a and 53h. Each section 53( ...id i533:provided with an arcuate recess Sil to receive annular flange 56 formedon the inner end of a friction collar El. The annular iange SLS servesto hold the sections and 53h in alignment with each other. The sectieormng the feed housing 53 are snugly receA -ed frictionally engagedwithin a barrel ES formed of plastic or metal.

A plurality of tapered fingers 59 are ffrmed on the outer end of theguide tube 5i for engagement by an annular clutch collar 6i which actsto move the lingers 59 into clutching engagement against the lead 52when thc guide tube 5l is moved inwardly to its position shown in Fig.The guide tube 5l is normally urged to its inner position by means of ahelical compression spring interposed between a shoulder E3 formed onthe guide tube 5l and a bearing Eli formed on the split feed housing 53.During inward movement of the guide tube 5l, it is brought to rest byengagement of the shoulder against bearing G5 formed on the feed housingA. si. table cap 6l is secured to the end of the guide tube 5l forengagement by the thumb of the user in reciprocating the guide tube toimpart a step-by-step outward movement of tfie lead During forwardmovement of the guide tube 5i the fingers 59 are held in tightengagement against the lead 52 by means of the clutch collar E l. As theguide tube approaches the forward end of its stroke, the clutch collar6| is brought to rest against a shoulder 61 formed on the feed housingto permit the resilient lingers 59 to move out of clutching engagementwith the lead 52. After release of the clutch fingers 5d from theirengagemcnt with the lead 52, the guide tube 5l is returned to its normalposition by means of the helical compression spring 62. As the guidetube 5! approaches its normal position, the clutch collar Si is broughtto rest against the bearing t@ and to wedge the resilient lingers 59inwardly for clutching engagement against the lead 52. During the returnstroke of the guide tube El, the friction collar 5l serves to hold thelead 52 against axial movement.

It will be noted that each of the two pencil constructions shown anddescribed embodies a. split feed housing for enclosing a guide tube, thefeed housing being divided longitudinally along diametrically opposedsides to form two half sections which are maintained against relativeaxial displacement by means of an annular flange disposed in arcuaterecesses formed in the half sections. During assembly of the mechanicalpencil, the guide tube is first enclosed within the two sections formingthe feed housing, and the feed housing is then forced into the barrel ofthe pencil for snugr frictional engagement therewith. If the pencilshould become inoperative for any reason, it is a simple matter toremove the feed housing and other parts from the interior of the barrelto repair or replace parts. By forming the feed housing in two sections,the cost of manufacture is greatly reduced as the sections may beinexpensively formed by die-casting or stamping operations.

While this invention has been shown in but two formait is obvious'tothose skilled in the art that it is not so limited but is susceptible ofvarious changes and modications without departing from the spiritand`scope of the claimed invention.

I claim as my invention:

l. In a mechanical pencil, a tubular housing divided longitudinallyalong diainetrically oppositesides to form twoisimilar abuttingsections, a tubular barrel snugly enclosing said housing, a guide tubemounted within said housing to receive a writing lead, means operableresponsive to movement oi saidguide tube relative to said tubularhousing to movefa writing lead longitudinally through said guide tube,and a member mounted in one end of said housing, said member having anannular. flange disposed Within and preventing relative longitudinaldisplacement of the two sections forming the housing.

2. In a mechanical pencil, a tubular housing divided longitudinallyalong diametrically opposite sides to form two similar abuttingsections, one end of said tubular housing being formed with an internalannular groove, a tubular barrel snugly enclosing said tubular housing,a guide tube mounted within said housing to receive a .f iting lead,means operable responsive to movement of said guide tuberelative to saidhousing to move a writing lead'longitudinally through. said guide tube,a member mountedin one end of said housing, said member having anannular flange disposed within said internal' annularY groove to preventrelative longitudinal displacement of the two sections forming thehousing.

3. In a mechanical pencil, an internally thread'- ed tubularhousingdivided longitudinally along diametrically opposite sides` to lform twoabutting sections, a tubular barrel snugly enclosing said housing, aguide tube mounted witl'iinsaidv housing to receive a writing lead, saidguide tube having a longitudinally extending slotY formed therein, aplug mounted within said guide tube, a shoulder provided on said plugand extending outwardly through the slot foi-med in said guide tube forengagement' by the threads of said internally threaded housing, and amember mounted in one end-of saidhousing, said member having arrannularflange disposed within and engaging the two sections of the housingagainst relativelorigitudinal displacement.

4; In a mechanical pencil, a tubular housing divided longitudinallyalong diametrically Vopposite sides to form two abutting sections, atubular barrel snugly enclosing said housing, a guide tube mountedWithin said housing to receive a writing lead, resilient fingers formedon one end of said guide tube, a clutch sleeve mounted on said guidetube to engage and move said resilient fingers into rictional engagementwith a writing lead, and shoulder means formed on said housing to movesaid clutch sleeve into and out of engagement with said resilientiingers responsive to reciprocatory movement of said guide tube.

5. In a mechanical pencil, a tubular housing divided longitudinallyalong diametrically opposite sides to form two abutting sections, atubular barrel snugly enclosing said housing, a guide tube mountedwithin said housing to receive a writing lead, resilient fingers formedon one end of said guide tube, a clutch sleeve mounted on said guidetube to engage and move said resilient fingers into frictionalengagement with a writing lead, shoulder means formed on said housing tomove said clutch sleeve into and out of engagement with said resilientlingers responsive to reciprocatory movement of said guide tube, and ahelical compression spring interposed between said housing and guidetube to normally hold said clutch sleeve in engagement with saidresilient fingers.

6. In a mechanical pencil, a tubular housing divided longitudinallyalong diametrically opposite sides to form two abutting sections, atubular barrel snugly enclosing said housing, a guide tube mountedwithin said housing to receive a writing lead, resilient fingers formedon one end of said guide tube, a clutch sleeve mounted on said guidetube to engage and move said resilient ngers into frictional engagementwith a writing lead, shoulder means formed on said housing to move saidclutch sleeve into and out of engagement with said resilient fingersresponsive to reciprocatory movement of said guide tube, a helicalcompression spring interposed between said housing and guide tube tonormally hold said clutch sleeve in engagement with said resilientngers, a friction sleeve to snugly receive and engage a writing lead,and annular flange means provided on said friction sleeve to engage andmaintain the two sections of the housing against relative longitudinaldisplacement.

GARY LYNN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,568,950 Ballou Jan. 5, 1926FOREIGN PATENTS Number Country Date 210,979 Great Britain Feb. 14, 1924

